Duke Trustee David Rubenstein has donated $5.75 million to the university's Sanford School of Public Policy.

The gift will be used in three areas, Duke officials said in announcing the gift Tuesday. It will provide $3.5 million for the school's endowment to support its program in Environmental and Energy Policy; $1.125 million will be used to fund a speakers series, and $1.125 million will support internships for master's students.

The gift lets Sanford, which recently transitioned from an institute to a formal "school" designation, hit a $40 million fundraising benchmark. The school ultimately hopes to raise $65 million.

Rubenstein is a Baltimore native and 1970 Duke graduate. He is the co-founder and managing director of the Carlyle Group, one of the world's largest private equity firms. Rubenstein Hall, which opened in 2005 on campus, bears his name in recognition of a previous $5 million gift.